Over the decades diesel and gas engines have evolved with basically three different types cylinder block and liner configurations. The integral bore cylinder block, top flanged liner and spacer plate and block combination and the mid supported liner spacer deck block arrangement.
The integral bore cylinder block is generally used for engines where cost, weight and size are the driving force behind the design and durability, and reparability is secondary. This type engine is generally considered light to medium duty.
The top flanged liner and cylinder block have been the industry standard for heavy duty diesel engines for decades. Top flanged liners are hardened for long life goals and easy reparability in case of cylinder bore damage. The engines can be rebuilt to like new at major overhaul by installing new liners.
The mid supported cylinder liner has the features of the conventional flanged liner and in addition permits the cooling fluid level to be raised to the top of the cylinder liner. The advantage for this system is the ability to raise the top ring of the piston to near the top of the piston thus reducing crevice volume in the combustion area. Crevice volume is a factor in lowering fuel consumption and emissions.
Although many of the major deficiencies associated with engine cylinders have been addressed they all fall short of maximization. In this regard, there is left the need for improvement in the areas of emissions by further reducing crevice volume. Crevice volume can be further reduced by maximizing the height of liner cooling to the bottom of the cylinder head. This would allow the piston rings to be placed closer to the cylinder head which reduces crevice volume. Also, by the elimination of clamping on the cylinder liner flange as in the mid or top mounted cylinder liners, undesirable emissions may be reduced. Clamping causes cylinder liner distortion. Without clamping, cylinder bore roundness may be maintained. Cylinder roundness facilitates good piston ring sealing which contributes to a reduction in undesirable engine emissions.
The present invention is directed to overcoming one or more of the problems as set forth above.